SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '096d03310adace4312fb5bd9b53dda01dc036d5a364a3e1d507a88b1a8fe5f67' 
  AND token = 'x2orqmsFBYdmipcKG6dPAE2EdrCvLCCwAJlR77XlAPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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