SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c11da90d18f2ec7ddebda60b2f0933e41dbb914dabad67e6ecf87352c981f3fd' 
  AND token = 'rRZorDMGfua8jxASrffSfuxNsFfV+CuswAUuXVHX7lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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