SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31bc4db96f70df8d73cb22cfcc9002b765aa463742df335e66a48774b08d00cd' 
  AND token = 'Lh2p+COhlkNPqYSqSCPuKeFM4cIxXQgcknV9rn8mxSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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