SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '703eba7568888cf549cfef24cabe0a4a0cfd5814f923c7865a27b0da77b67bd9' 
  AND token = 'ov5KeQpFzy7euiuhbeydhmj6V5xRmN9Xr9fPDUbAgDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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