SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77e5f5a112f3806dba39f024e328c84b23291fd24f3dabc262dd8ee0c455690e' 
  AND token = 'P4wxm8DOjzokQdELF0b+KvjP0nZH/LJAEaid6g/B5kM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}