SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1b90ac5b065902d34acf1542d354757e0269b9b587abc08096fe333cf232c8aa' 
  AND token = '42P7+v18y+JIr/BcORjXm6sgaQiiMy17AuBIqi3D9Ko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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