SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cb3bb9f7f62f5441be89c09302df5451a69e8194847926bba7b333cfaec523a' 
  AND token = '6pGi1VPjQk6Ozfx2ncUcV8hNyY1ahaIjboMegHuv3FY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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