SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4801143955f23681b0f0028539ba70f640d65af20cdce7f06897d0714ff043b8' 
  AND token = 'WVWjvTWgobu1sRDDm6IfKPHDyh5XqM4zT3C76xNslLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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