SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2f69da4743b1959852032dbb47811cceffedcdb98834f7d0a84a990fafd135f' 
  AND token = '6lVNr2OTv/Q35/gjMW5oR848VRIuhTnXS5NezqpI/VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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