SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e577bf91abafec764b7932cedad992cb0d61df09f618c8945ebadc9cba9164df' 
  AND token = 'FRSey0HjL0pbQfdR7jQeoMHO3TCf7bUNWUNf5h+qll4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00118

JSON explain

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