SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2590b0f14342316cf6fc3dc70b1fb631f4ff05464a5a99398acbfa7ead87fd94' 
  AND token = '4b9i+DlfIj0GPAhY1wuE1BUK6FOUVPv/Y+8RWozVJj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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