SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '967d43158fb210a23ac52ea1a02ceb42f0bdd57c04b5a46259dbb839bd853454' 
  AND token = 'cEUidPAdD+/c/1fslhfnuIRdAE5XZFx4j0LIRGm7qaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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