SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46fadd867e4974331830f63efae4db2da15da5907cf56822ee0cdc51c94d54be' 
  AND token = '0zo9e4Fm7chgrqTS2JdOEJHtvgqVA09lmv8uBSHup1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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