SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1db6c0b3eba4454729d712b86f5b26b4af2fbbc93f12fe8201c33f5d5f7d4b4' 
  AND token = '4Bc9dw+Lg3cdxXI9t0qh3rhISLbMriu7irwDz1stljI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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