SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91c4315669bbe990f6044dbcd4ee813dface03ea28412ceb6e613bbc192a536d' 
  AND token = 'pQbATFnk02RsRxb3dgOUcfK+agwyOsG3F+rGrHqJ2Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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