SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6214e68af52e719b1ef5652c75a25c53d72547710c4b392606ffb173553a3652' 
  AND token = 'eW/voK1uYQb9WG1VN1ZdqS2AUUiJ7PyF/0zAEmEN+Jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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