SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ed872c26b00be7476f50c1962c6012c6f512c1d5fe4cfae9572e631b9e75830' 
  AND token = 'noQwdLmSsztXko46/nf+NHE9VHmvgNXfRCaEYL9hbNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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