SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a39bf459ba42d35254f3a91eaba0c7e3d0f1d24f974e3436ce0607e68468cd6e' 
  AND token = '7BsacZOrl6RTTIVNx1OMvQ15606qvhpS+ov0eqNBhxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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