SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e61ba86af5988864b0e6c17b1948693f10e240dfc3360874ed9497b4f403aa44' 
  AND token = 'THCjO6CNDAebXnvcxtFuyvF0DXcvdEQCpqxFjwEzaV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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