SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57c45db25ed9d70de79c53b973d82557d2095057625d0f6042787a392a4e64c3' 
  AND token = 'S5RoSmcpewepLP3gycDFsOFFFjSvXGzV/R2fcC4A+wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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