SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c80f3616d3a6e55ba35c81980aaa43d1e75ece3291e34b0d00c26bad55e2fa62' 
  AND token = 'Txkr1bmlWHh7nsLSPcNC5Hz3WH/IddETOKwYNGWhm1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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