SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cb3d5a624bd20edd404a945e09bec13cec2471c6a3228b2b32ec318aef6a20e' 
  AND token = 'IPKriLtjBAkyr/hEO3F+1vNzzkVtg7JgGXRKAVrrCFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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