SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d1fca5e91ba4c16d81654ce5121c3e84b33ea1c5fdf649ed14ddfa466e52771' 
  AND token = 'eI6yAeCfqoVx6lf371ilWE6KeBcE60XMmm3tDW0P51Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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