SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12e174c3f8b06c427a6c007ad7411b18fad3a619378e0ec8f0e60ab11e5c26a5' 
  AND token = 'gOCgE92+9bRbPzBFdwfcvhnNmHFwJQGUqBJw9698TP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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