SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c18186f2f25e8f5bf24290f94c8f3d5cf0d3e0d21e83b01ecb823946476ceb' 
  AND token = 'Ir86/rQpNwQm8DXCqcN2Dyglr4WdBNE22lp3NlW65dI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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