SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c72d77f6511b132d386ca37a8333816ff2e7a86390820755a9005a649a78af11' 
  AND token = 'XUPtNVcnp5YcZ3+L7qZBP+lnhq5bndXJE3wYgT89HRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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