SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32fbd3a15fab0401983a939d785046840fc256e0646499503dac76dc75c5d9ac' 
  AND token = 'A7G6HgaD5YUTmEJu9JyTBd4Y3gVtKC3vFO1rB0/zAfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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