SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6913535c8f061e699019cc200779a6974b216b19d36d69758b36c6285bbd23d6' 
  AND token = 'zXFwnGzGVPlD4s52f0UgDDDpmtVuCIfeif4NXNkFMbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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