SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b70b5d625c03c031a7ed139f173965f981dbb34ba6f3d40db75291a11f71220' 
  AND token = 'by+Nn11XIEVY+rySDCREXDCTrr1AX8fTSbZPnL5DfcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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