SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bcaf482b0a4712c1839c32e9125e7532d75a5dde6f3951d3343b17b4c8a0276' 
  AND token = 'uhzhGWXxSFJErOxKsGAtt4230dq/ow6I2d1NELBxaao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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