SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d5f347de56af0bd3ec8f2f94fc86ce06e1fb173ad2c3c1e2232dedca3de7897' 
  AND token = 'CEskoQP+okiGoG+JqY7gVUBP6byE7z2C/dKURPxh3FQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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