SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f6034e3fd58a13a2936f908709ff811b096be883343f87987e6c1b07a2f2f25' 
  AND token = 'krBxZGvkMitJ1D5TZTRbVTNplYmvXMAqzh+VgS8tsYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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