SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a0fad0fba34d65bdb49d0a0eb8b97245d448cbea0b5cad06bd3c50dce33dffe' 
  AND token = 'XCcww4DPU5F9B/Lkf1Bt/NOQdGnTd1Kt6wZ/ulOCaRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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