SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0c4c9b78d277c38f6fc6c06b215de74d049eba68d26114bcabcfb7997f69789' 
  AND token = 'n6PBB+R3w/AjqESn8HKPqslseKclEEJjQDYW44IXCGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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