SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e84ac715e21028bd83a2cfb1ca1bf2f5bccf01809d13eec9e718ec048f1bf722' 
  AND token = 'vU+O3aOyQXS1UGijlS9YEFDENFW+KqNc+iyMslsIiSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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