SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58519fa09898bf9116baa038ad2d5be4358895b65c825e351eea6617b3a029e5' 
  AND token = 'MVWAriFJuZtPdbc0Adm1ofL+/Rd7MXUnzu8edQBEYYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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