SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7084c7a7952654a3a60805fd0cfb896a22b5f6463d4c6036754af0860a729f75' 
  AND token = 'x8y9qpw5OJjS9fxfbIr8WVBd6XWoUhbw/s+bpLBXKsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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