SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61e731e241893c391b73feb206cb0ae174709009ac15c11feff554afb5d657d2' 
  AND token = 'oQlz8ELF1bfdm31jsrkehwoJktm+z75BCWaCpr5Jb1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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