SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ac5858d5e183981fff66d32ad4d8da147dd304c006ca4aee0af331386b60bad' 
  AND token = 'CaP1tSMXAwOu8KXNLJcxMDXLuJcaQF0wlfg02+1tjjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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