SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fefafa436eead414bb5398f371e595fadbba3f8539f20a42f553213824fa8004' 
  AND token = 'fRK3L7C9/yEwhevJQhGRSzh+eMHnXSh5+/QWNN80FqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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