SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54c27163ff36305ab7e2a7234e8ba178ec7493ec7854ad6cf8f44f28c3bd4a8b' 
  AND token = 'GvSdQgYM39Q8lfUH7DkKG97VACaB0VPTjSiZWID7AwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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