SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55a993ea7878a3aa886f0910a31cd58c42d9a5f9ba343ef466f1b90c3a258efd' 
  AND token = 'AMGcsQFtnCAh0V9Flox/kG5/LeQdgMWjAkL6Uo1Rzs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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