SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd955a2d386596760b8c14394e8f98fa356e274c23223ee4107732c15023a8a29' 
  AND token = 'DWa2FP1/PSHMFr8JIkLz4HHHvBJznfPGbIQMGgNBilo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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