SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac25b361bbb0ce549124fabdd1b223ab9b847c077688826f6671e3955dd14ff7' 
  AND token = '7dnYKCk+2E6kBPLq6PCaQsdRnG/rrkg6udu421FMJvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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