SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '001d42818cbea9ddea1a2dde5aa7be5c14b66695ab50fa38d2cfcb76226467d7' 
  AND token = 'q0CkJOZQoYo28AtqsOmx4s5q6TBF+0/VZ+u5HsaEsGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}