SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd38d50425395936a1030f06c8acc27e921922e48f1e8994c50496db7189fb1aa' 
  AND token = 'SQ2rhM0ZGmUXnXrUcBy7h/WwhYrd3BOIo7Yx90L80+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}