SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f61cfc4615b82d0ef04bef51846a80078439af0eb131bd3de5a347c6ca5b210e' 
  AND token = 'krn3hNgTPIemS3Guzhp/Zd11oIG/EQ1McpV9sEaCUsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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