SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1ef9acdc007377228da04af78aec36850b809a7fa0d1fe31bb791e3f31b3e7a' 
  AND token = 'VgoEEIa+WwCXWQZs9vD2i6u6KnRpUSV5Vg+qJRG28fs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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