SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9146fc8fef69b690c24a8f56602dc2673dccf229605f520354be80cc898a8a5' 
  AND token = 'nbxV0WjcGAECNXd5prww//zetlgFHOYiCsTHqMGAieE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}