SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7205ebca41600f23a7f82d880b55082e8b06be6846afeeeb5b81505c868f3c4' 
  AND token = 'bP+zvQKLiMxXZ4f3PmKLdJNLKrFVV+AYw/Nw49yqxwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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