SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ba0f90d707383d1c71402ed289664259ebccab26db264b5be942fd96f826b8b' 
  AND token = 'SVDali55Ki2xfghTnM5VU4YIhHp+FUQFden/Cx1BfxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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