SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d334e301b7295766c1a9f1f748eebc7d0f99e153202859ea2e5d14cc71769b1' 
  AND token = 'Qfgv/g1DrMIe2gYwl6HvYZUPh+DxB2+jBkwNij1qn58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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