SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e82d916f74446cd7d96522a64c0b3f5e4e134030b92ab704b4c1fb9417254535' 
  AND token = 'wSNYd5XDPHwDmWz5IX37ehOUBIrhWFo7pS9HvXzTMfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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