SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b07cefcd56fbf8f219f022f81b4d8a65c100085358156218cfcac490be1bf356' 
  AND token = 'TPMZvzRewO3UT/PWbzwLu3p3lb1MtufMzqAiQJj5TeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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