SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '899c5518982dd2e4c98dac105860c3a0a1594840693d09847fb59d4a04d77cb8' 
  AND token = '0tgCj0Zn7qyEXwtr1rskxUfBimli6COtmHC2IfF4z1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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