SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '734e2a66b8741dc465bb61bc2f46d916d802cc5d6f82dd31159f0b758911e2b0' 
  AND token = 'CCHFHj92DV+envjVgaXHTZJqkc3uvOuBZIQ/GrrXncg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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