SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40b2cfef3766aa6eeb0931c39907c390e424fb30c841e48afd7259bec4117074' 
  AND token = 'uoB+OVCAW7qjgcGRdIOhTiN5ZMY4ejQppV8WvvYrQPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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