SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fdb3e45f6c83c70b18233489373b1f6d6ae1a30750a66a932394c8e3be2483c9' 
  AND token = 'g4gMX8dGQLbhZ3qome79bZvXd4LWangY6+no6CCKZwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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