SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c91448276fecde24482ee75cf741fcabc4f96a1806b51bf01c16462b747452d' 
  AND token = 'tyC/oYynroQa3uRTLIuMU0eXtgPDLLE601/DL82/G3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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