SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04c6a79729222d22824a5ec107dd49e382028b36682be55b1521e361a0e3f26c' 
  AND token = 'ehUtfoYY2YIdJqx3WpemxEaRCjne+Ov4jV4i01Pwsmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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