SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '269076480f166ef891f895dde38ca1d227a02e432daf893f097d44c737107059' 
  AND token = 'gf/Mb/9uLFwk3z4YYXT8jtn+aepfVSCxLHvUVGW7aEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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