SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ade2d74e0ed0390ddd8ffa02202b360f4e5a88131cc4d720633d3addd1bea186' 
  AND token = 'BW/PQtgCFEMmtxRID9JqIPADOaEP0Dg1qOQgAsBuoEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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