SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ac66f52451e5614c1a93e2e2fb4620c7613bc92e53680f7a3c3552077a698cd' 
  AND token = 'EYQaZAORQBwGCmpUZ7NJJWbcHkfKVUgNYraZieFPd/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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