SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '663ae7ce378825e1e6658ab0b3764be0e316191f67b6513586490af777bcc78f' 
  AND token = 'lK+Zmnkrjvs0eQPGFtzEJrNyaOtG3+QweD2VZ/5vxas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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