SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afc29412c900b4c8ba41abcec2d8d02dce5c0d0c996c425b33406a4183596e82' 
  AND token = '6wTGE+lmrU2uIRZtP5So6Mx8r9Q3b72rvBnY1YbCtng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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