SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7566b06b436f97045849ee0840f1321d3a3340ec4d59c17711ec4657a47af775' 
  AND token = 'vPKrPGXGovy6fdoe7U8bBVPm9NTKsJAVV7KVwvSroaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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