SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '626a93719d572351ed42002f838b4ee35734bd0ab12a0dcc51101a45abdaab1e' 
  AND token = 'G4zBYP3imeAM6lVCcQw3Gvo4LZluLJOzg58eJWiCFMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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